Thin film evaluation method, mask blank, and transfer mask

ABSTRACT

Provided is a thin film evaluation method for a transfer mask which is adapted to be applied with ArF excimer laser exposure light and comprises a thin film formed with a pattern on a transparent substrate. The method includes intermittently irradiating pulsed laser light onto the thin film to thereby evaluate the irradiation durability of the thin film.

This is a Divisional of application Ser. No. 13/109,655 filed May 17,2011, which claims priority from Japanese Patent Application No2010-115833 filed on May 19, 2010, the contents of all of which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

This invention relates to a method of evaluating the irradiationdurability of a thin film and to a mask blank and a transfer mask. Inparticular, this invention relates to a method of evaluating theirradiation durability of a thin film of a transfer mask adapted to beused in an exposure apparatus using exposure light having a shortwavelength of 200 nm or less and further relates to a mask blank forsuch a transfer mask and to such a transfer mask.

BACKGROUND ART

Generally, fine pattern formation is carried out by photolithography inthe manufacture of a semiconductor device. A number of substrates calledtransfer masks are normally used for such fine pattern formation. Thetransfer mask comprises generally a transparent glass substrate havingthereon a fine pattern made of a metal thin film or the like. Thephotolithography is used also in the manufacture of the transfer mask.

In the manufacture of a transfer mask by photolithography, use is madeof a mask blank having a thin film (e.g. a thin film made of a materialcontaining a transition metal) for forming a transfer pattern (maskpattern) on a transparent substrate such as a glass substrate. Themanufacture of the transfer mask using the mask blank comprises anexposure process of writing a required pattern on a resist film formedon the mask blank, a developing process of developing the resist film toform a resist pattern in accordance with the written pattern, an etchingprocess of etching the thin film along the resist pattern, and a processof stripping and removing the remaining resist pattern. In thedeveloping process, a developer is supplied after writing the requiredpattern on the resist film formed on the mask blank to dissolve aportion of the resist film soluble in the developer, thereby forming theresist pattern. In the etching process, using the resist pattern as amask, an exposed portion of the thin film, where the resist pattern isnot formed, is dissolved by dry etching or wet etching, thereby forminga required mask pattern on the transparent substrate. In this manner,the transfer mask is produced.

For miniaturization of a pattern of a semiconductor device, it isnecessary to shorten the wavelength of exposure light for use inphotolithography in addition to miniaturization of the mask pattern ofthe transfer mask. In recent years, the wavelength of exposure light foruse in the manufacture of a semiconductor device has been shortened fromKrF excimer laser light (wavelength: 248 nm) to ArF excimer laser light(wavelength: 193 nm).

As a type of transfer mask, a halftone phase shift mask is known apartfrom a conventional binary mask having a light-shielding film patternmade of a chromium-based material on a transparent substrate. Thishalftone phase shift mask is configured to have a phase shift film inthe form of a light-semitransmissive film on a transparent substrate.This phase shift film in the form of the light-semitransmissive film isadapted to transmit light having an intensity that does notsubstantially contribute to exposure (e.g. 1% to 20% at an exposurewavelength) and to provide a predetermined phase difference. Thehalftone phase shift mask has phase shift portions formed by patterningthe phase shift film and light-transmissive portions formed with nophase shift film and adapted to transmit light having an intensity thatsubstantially contributes to exposure. The phase shift film is formed sothat the phase of the light transmitted through the phase shift portionsis substantially inverted with respect to that of the light transmittedthrough the light-transmissive portions. As a consequence, the lightshaving passed near the boundaries between the phase shift portions andthe light-transmissive portions and bent into the others' regions due todiffraction cancel each other out. This makes the light intensity at theboundaries approximately zero to thereby improve the contrast, i.e. theresolution, at the boundaries. As a material of the phase shift film, amolybdenum silicide compound, which is a material containing molybdenumand silicon, is widely used.

Further, there is a special type of light-semitransmissive film which ismainly used as a thin film for forming a pattern of an enhancer mask.Light-semitransmissive portions formed by this light-semitransmissivefilm transmit exposure light at a predetermined transmittance, butdifferent from the halftone phase shift film, the phase of the exposurelight transmitted through the light-semitransmissive portions becomesapproximately the same as the phase of the exposure light transmittedthrough light-transmissive portions. Also as a material of thislight-semitransmissive film, a molybdenum silicide compound, which is amaterial containing molybdenum and silicon, is widely used.

Further, in recent years, there has also appeared a binary mask using,as a light-shielding film, a molybdenum silicide compound which is amaterial containing molybdenum and silicon.

SUMMARY OF THE INVENTION

Following the reduction in exposure light wavelength in recent years,however, mask degradation due to the repeated use of a transfer mask hasbecome notable. Particularly in the case of a phase shift mask, aphenomenon occurs in which the transmittance and the phase differencechange and further the line width changes (increases) due to theirradiation of

ArF excimer laser light (wavelength: 193 nm) as exposure light. In thecase of the phase shift mask, such changes in the transmittance andphase difference are serious problems that affect the mask performance.If the change in the transmittance becomes large, the transfer accuracyis degraded. Along with this, if the change in the phase differencebecomes large, the phase shift effect at the pattern boundaries isdifficult to obtain so that the contrast at the pattern boundaries islowered and thus the resolution is significantly reduced. Further, thechange in the line width degrades the CD (Critical Dimension) accuracyof the phase shift mask and finally degrades the CD accuracy of apattern-transferred wafer.

The problem of the mask degradation due to the repeated use of thetransfer mask is significant particularly in the case of a phase shiftmask in which a transition metal silicide compound, a materialcontaining a transition metal and silicon, is used as a material of aphase shift film. But, also in the case of an enhancer mask in which atransition metal silicide compound, a material containing a transitionmetal and silicon, is used as a material of a light-semitransmissivefilm, there have arisen problems of a change in the transmittance of thelight-semitransmissive film, a change in the phase difference, and adegradation in the CD accuracy due to a change (increase) in the linewidth of the pattern.

Also in the case of a binary mask in which a material containing atransition metal is used as a material of a light-shielding film, thedegradation in the CD accuracy due to a change (increase) in the linewidth of a light-shielding film pattern arises as a problem in the sameway.

According to the study of the present inventor, the background of theproblem of the mask degradation due to the repeated use of the transfermask is assumed as follows. Conventionally, for example, when haze (e.g.foreign matter composed mainly of ammonium sulfide and generated on themask) is generated, cleaning is carried out for removing the haze. Thiscleaning entails an unavoidable film loss (dissolution) of alight-shielding film or a light-semitransmissive film and thus, roughly,the number of times of cleaning determines the mask lifetime. However,since the number of times of cleaning is reduced due to an improvementto haze in recent years, the period of time of the repeated use of amask is prolonged and thus the time of exposure to exposure light isprolonged correspondingly. As a consequence, the problem of the maskdegradation has been actualized and, particularly, a problem ofirradiation durability against short-wavelength light such as ArFexcimer laser light has been newly actualized. Nevertheless, since thetransfer mask manufacturing cost has been increasing following thepattern miniaturization, there is an increasing need for a longerlifetime of a transfer mask.

Also conventionally, a measure has been taken to suppress the change inthe transmittance of the phase shift film and the change in the phasedifference due to the irradiation of exposure light. For example, aphase shift film composed mainly of a metal and silicon is heat-treatedin the atmosphere or an oxygen atmosphere at 250 to 350° C. for 90 to150 minutes (see, e.g. JP-A-2002-156742 (Patent Document 1)) or a caplayer composed mainly of a metal and silicon is formed on a phase shiftfilm composed mainly of a metal and silicon (see, e.g. JP-A-2002-258455(Patent Document 2)). However, a further improvement in irradiationdurability of a film to exposure light is required in the course of thereduction in wavelength of exposure light in recent years.

This invention has been made under these circumstances and has an objectto provide a transfer mask in which the irradiation durability of a thinfilm made of a material containing a transition metal against exposurelight having a wavelength of 200 nm or less is evaluated and guaranteed,and further to provide a mask blank for such a transfer mask and amethod of evaluating the irradiation durability of such a thin film.

The present inventors have assumed a cause of the degradation of thetransfer mask due to its repeated use becoming notable following thereduction in exposure light wavelength, as follows.

The present inventors have examined a pattern of a phase shift film madeof a MoSi-based material and subjected to changes in the transmittanceand phase difference and a change (increase) in the line width due tothe repeated use. As a result, the present inventor has found that amodified layer containing Si, O, and a little Mo is formed on thesurface layer side of the MoSi-based film and that this is one of maincauses of the changes in the transmittance, the phase difference, andthe line width. The reason (mechanism) for the formation of such amodified layer is considered as follows. That is, the conventionalsputtered MoSi-based film (phase shift film) has structural gaps and,even if annealing is carried out after the film formation, the change inthe structure of the MoSi-based film is small and thus these gaps canhardly be removed. On the other hand, for example, oxygen (O₂) and water(H₂O) are present in the atmosphere and ozone (O₃) is produced byreaction of oxygen (O₂) with ArF excimer laser light in the course ofusing a phase shift mask. The oxygen and the produced ozone enter thegaps of the MoSi-based film and react with Si and Mo forming the phaseshift film. That is, when Si and Mo forming the phase shift film aresubjected to irradiation of exposure light (particularlyshort-wavelength light such as ArF excimer laser light), they areexcited into a transition state. In this event, if the ozone or the likeis present around them, Si is oxidized and expanded (because SiO₂ islarger in volume than Si) and Mo is also oxidized. In this manner, themodified layer is formed on the surface layer side of the phase shiftfilm. Then, while being accumulatively subjected to the irradiation ofthe exposure light due to the repeated use of the phase shift mask, theoxidation and expansion of Si further proceed and the oxidized Modiffuses in the modified layer to be deposited on a surface thereof andsublimated as, for example, MoO₃, and as a result, the thickness of themodified layer gradually increases (the occupation ratio of the modifiedlayer in the MoSi-based film gradually increases). This phenomenon ofthe formation and enlargement of the modified layer is significantlyobserved in the case of short-wavelength (200 nm or less) exposure lightsuch as ArF excimer laser light having energy necessary for exciting Siand Mo of the phase shift film into the transition state. Such aphenomenon is not limited to the MoSi-based material, but also occurs inthe case of a phase shift film made of a material containing anothertransition metal and silicon. Further, this also applies to an enhancermask having a light-semitransmissive film made of a material containinga transition metal and silicon and to a binary mask having alight-shielding film made of a material containing a transition metal.

Based on the elucidated fact and consideration described above, thepresent inventor has further continued intensive studies.

In the meantime, in a semiconductor exposure apparatus, particularly, inan exposure apparatus called a scanner, a wafer stage with asemiconductor wafer placed thereon and a reticle scanning stage with areticle, serving as a master of a circuit pattern, placed thereon aresynchronously scanned in mutually opposite directions at a predeterminedspeed ratio so that exposure of the semiconductor wafer is carried outduring the scanning.

The irradiation durability is evaluated by a simple evaluation using anacceleration test in which continuous laser light having an energydensity higher than that which is used in the above-mentioned scannerexposure is irradiated.

The present inventor has advanced the research and development of asimple evaluation of the irradiation durability using an accelerationtest. As a result, although it is generally considered that a severecondition such as, for example, a high energy condition is suitable as acondition of an acceleration test, the present inventor has found thatthere are conditions of an acceleration test that can relatively improvethe correlation with the result of an irradiation durability evaluationof a mask (result of mask lifetime) when semiconductor devices areactually manufactured by scanner exposure. The present inventor hasfound that, in a simple evaluation of the irradiation durability usingan acceleration test, the change amount (increase amount) of the linewidth changes depending on an irradiation method and an irradiationcondition. Specifically, the present inventor has found that, byreplacing, in an acceleration test, an irradiation method ofcontinuously irradiating laser light onto a fixed portion with anirradiation method of intermittently irradiating pulsed laser light, itis possible to carry out an evaluation having a higher correlation withthe result of an irradiation durability evaluation by actual scannerexposure. The reason for this is considered to be that it is possible toreproduce an irradiation state (action) which is similar to an actualscanner exposure irradiation state in which exposure light is notcontinuously irradiated onto a fixed portion.

According to this invention, it is possible to carry out a high-accuracyirradiation durability evaluation with only a small difference from theresult of an irradiation durability evaluation by actual scannerexposure. According to this invention, as compared with the case wherean irradiation durability evaluation is carried out using a scannerexposure apparatus or an equivalent apparatus, the evaluation iscostless and is efficient because it is an acceleration test.

This invention has the following structures.

Structure 1

A thin film evaluation method for a transfer mask adapted to be appliedwith ArF excimer laser exposure light and comprising a thin film formedwith a pattern on a transparent substrate, the method comprising:

-   -   intermittently irradiating pulsed laser light onto the thin film        to thereby evaluate irradiation durability of the thin film.

Structure 2

The thin film evaluation method according to Structure 1, wherein thethin film is made of a material containing a transition metal andsilicon.

Structure 3

The thin film evaluation method according to Structure 1 or 2, whereinthe pulsed laser light is intermittently irradiated to a degree thatdoes not cause heating of the thin film.

Structure 4

The thin film evaluation method according to any one of Structures 1 to3, wherein the pulsed laser light is emitted by intermittent oscillationand is irradiated onto the thin film at its fixed position.

Structure 5

The thin film evaluation method according to Structure 4, wherein acessation period of the intermittent oscillation is 100 msec to 3000msec.

Structure 6

The thin film evaluation method according to any one Structures 1 to 3,wherein the pulsed laser light is emitted by continuous oscillation andis intermittently irradiated onto the thin film by relatively moving thethin film with respect to the pulsed laser light.

Structure 7

The thin film evaluation method according to any one of Structures 1 to6, wherein the pulsed laser light is irradiated onto the thin film in ahumidity-controlled atmosphere.

Structure 8

The thin film evaluation method according to any one of Structures 1 to7, wherein the pulsed laser light is irradiated onto the thin film in anenvironment where an amount of a chemical contaminant in an atmosphereis controlled.

Structure 9

The thin film evaluation method according to any one of Structures 1 to8, wherein the thin film is a light-semitransmissive film made of amaterial composed mainly of a compound containing a transition metal,silicon, and one or more elements selected from oxygen and nitrogen.

Structure 10

The thin film evaluation method according to any one of Structures 1 to8, wherein the thin film is a light-shielding film.

Structure 11

A mask blank comprising a thin film whose irradiation durability isevaluated and guaranteed by the thin film evaluation method according toany one of Structures 1 to 10.

Structure 12

A transfer mask manufactured by using the mask blank according toStructure 11 and patterning the thin film.

Structure 13

A method of manufacturing a semiconductor device, comprising forming acircuit pattern on a semiconductor wafer using the transfer maskaccording to Structure 12.

Structure 14

A method of manufacturing a transfer mask adapted to be applied with ArFexcimer laser exposure light and comprising a thin film formed with apattern on a transparent substrate,

-   -   wherein the transfer mask has an evaluation pattern formed by        the thin film, and    -   irradiation durability of the thin film is evaluated by        intermittently irradiating pulsed laser light onto the        evaluation pattern.

Structure 15

A method of manufacturing a semiconductor device, comprising forming acircuit pattern on a semiconductor wafer using the transfer maskmanufactured by the method according to Structure 14.

Hereinbelow, this invention will be described in detail.

The thin film evaluation method of this invention is

-   -   a thin film evaluation method for a transfer mask adapted to be        applied with ArF excimer laser exposure light and comprising a        thin film formed with a pattern on a transparent substrate,    -   wherein the method comprises intermittently irradiating pulsed        laser light onto the thin film to thereby evaluate irradiation        durability of the thin film (Structure 1).

By intermittently irradiating the pulsed laser light onto the thin filmas described above, it is possible to carry out an irradiationdurability evaluation of the thin film which has a higher correlationwith the result of an irradiation durability evaluation by actualscanner exposure.

On the other hand, if the pulsed laser light is continuously irradiatedonto the thin film, there occurs a phenomenon which is different fromactual scanner exposure, and therefore, there occurs a state whichcannot be said to evaluate the intended irradiation durability. Forexample, in the case of carrying out a simple evaluation of theirradiation durability by continuously irradiating the pulsed laserlight onto the thin film, the change (increase) in the line width may beaccelerated so that it is possible to underestimate (judge defective)the irradiation durability of the thin film which should be evaluatedgood with a small change (increase) in the line width according to theresult of an irradiation durability evaluation by actual scannerexposure.

In this invention, “intermittently irradiating” or “intermittentirradiation” represents repeating irradiation and non-irradiation withrespect to a fixed position on a mask. For example, “intermittentirradiation” represents carrying out irradiation for a predeterminedtime S, then stopping or ceasing the irradiation for a predeterminedtime T, and repeating this cycle with respect to a fixed position (fixedportion) on a mask.

A method of intermittent irradiation may be a method in which the pulsedlaser light is emitted by intermittent oscillation and is irradiatedonto the thin film at its fixed position (fixed portion)(later-described Structure 4), or a method in which the pulsed laserlight is emitted by continuous oscillation and the pulsed laser lightand the thin film are moved relative to each other (later-describedStructure 6).

In this invention, as a transition metal, use can be made of molybdenum,tantalum, tungsten, titanium, chromium, hafnium, nickel, vanadium,zirconium, ruthenium, rhodium, or the like.

In this invention, the thin film may be made of a material containing,in addition to the transition metal, at least one of nitrogen, oxygen,carbon, hydrogen, inert gases (helium, argon, xenon, etc.), and so on.

In this invention, the thin film can be a light-shielding film in abinary mask or a light-semitransmissive film in a phase shift mask.

In this invention, the thin film may be made of a material containingthe transition metal and silicon (Structure 2).

This is because, as described above, when the thin film is made of thematerial containing the transition metal and silicon, the phenomenonremarkably occurs in which the line width changes (increases) due to theirradiation of ArF excimer laser light (wavelength: 193 nm).

In this invention, the thin film may be made of a material containing,in addition to the transition metal and silicon, at least one ofnitrogen, oxygen, carbon, hydrogen, inert gases (helium, argon, xenon,etc.), and so on.

In this invention, the thin film can be a light-shielding film in abinary mask or a light-semitransmissive film in a phase shift mask.

In this invention, it is preferable that the pulsed laser light beintermittently irradiated to a degree that does not cause heating of thethin film (Structure 3).

The present inventor has found that if the thin film is heated, theevaluation of the irradiation durability largely changes. For example,in the case of carrying out a simple evaluation of the irradiationdurability by continuously irradiating the pulsed laser light onto thethin film, the change (increase) in the line width may be suppressed sothat it is possible to overestimate (judge good) the irradiationdurability of the thin film which should be evaluated defective with alarge change (increase) in the line width according to the result of anirradiation durability evaluation by actual scanner exposure. The reasonfor this is considered to be that when the pulsed laser light iscontinuously irradiated so that the thin film is heated (generatesheat), there occurs a state where water is not present locally at aheated portion of the thin film. In order for a change in the line width(e.g. a phenomenon in which Si becomes SiO₂ to increase in volume) tooccur, the oxidation is considered to proceed in the presence of waterand oxygen and thus the presence of water and oxygen is considerednecessary.

In the scanner exposure, since exposure light is not continuouslyirradiated onto the mask at its fixed position (fixed portion), the thinfilm is hardly heated. In this invention, “a degree that does not causeheating of the thin film” is preferably the same degree that the thinfilm is hardly heated in the scanner exposure. Further, “a degree thatdoes not cause heating of the thin film” is preferably such that therise in the average temperature of the entire thin-film-coated substrateis 2° C. or less.

In this invention, it is preferable that the pulsed laser light beemitted by intermittent oscillation and irradiated onto the thin film atits fixed position (Structure 4).

Herein, “intermittent oscillation” represents carrying out pulseoscillation of a predetermined number N of pulses (shots), then stoppingor ceasing the pulse oscillation for a predetermined time T, andrepeating this cycle. On the other hand, “continuous oscillation”represents continuously carrying out pulse oscillation with no cessationperiod (a continuous oscillation mode).

In this invention, a cessation period of the intermittent oscillation ispreferably 100 msec to 3000 msec (Structure 5).

In this invention, the cessation period may be set to a time long enoughto prevent heating of the thin film. Although it depends on the energydensity of the laser light, if the cessation period is 100 msec or more,the heat is fully dissipated and thus is hardly stored. If the cessationperiod is longer, there is no problem of heat storage.

Although it depends on the energy density of the laser light, if thecessation period is set to 100 msec to 3000 msec or further to 500 msecto 1000 msec, it is considered possible to carry out an evaluationhaving a high correlation with the result of the scanner exposure.

In this invention, the oscillation frequency of the pulsed laser lightis preferably 300 Hz or more and more preferably 500 Hz or more. On theother hand, the oscillation frequency of the pulsed laser light ispreferably 2000 Hz or less and more preferably 1000 Hz or less. If it ishigher than 2000 Hz, the condition approaches that of the scannerexposure, but the cost becomes high.

The oscillation frequency of pulsed laser light in the scanner is 4000Hz to 6000 Hz. It is considered possible to carry out an evaluationhaving a high correlation with the result of the scanner exposure if theoscillation frequency of the pulsed laser light in the evaluation is setclose to that in the scanner.

In this invention, it is preferable that the energy density of the laserlight be adjusted low and the cycle of the intermittent irradiation forthe fixed position (fixed portion) on the mask be adjusted so that thethin film is not heated (does not generate heat).

The energy density per pulse is preferably, for example, about 2.5 to 15mJ/cm²/pulse. This is because, since the oscillation frequency of thepulsed laser light is lower than that in the scanner exposure, theenergy density higher than that in the scanner exposure is required inorder to obtain the same heat energy, but if the energy density isincreased, the thin film is heated.

The present inventor has found that there are conditions of anacceleration test that can relatively improve the correlation with theresult of the scanner exposure.

In this invention, it is preferable to control the respectiveconditions, i.e. the energy density, the oscillation frequency (numberof shots), the pulse width, and the cessation period, (particularly, tocontrol the balance of the respective conditions) so that there occurchanges (increase in line width, etc.) equivalent to, approximate to, orsimilar to changes (increase in line width, etc.) which occur in themask (reticle) by the scanner exposure.

For example, if both the energy density and the oscillation frequencyare extremely low, the energy is too low to cause any change in the thinfilm so that an irradiation durability test cannot be effected.Therefore, it is necessary to provide a certain amount of energynecessary for reaction.

For example, it is considered that although the reaction of change(increase) in the line width is promoted as the energy increases, if thethin film is heated to reduce water as a factor for change (increase) inthe line width, the reaction of change (increase) in the line width issuppressed. In this way, it is considered that the promotion of reactiondue to the increase in energy and the suppression of reaction due to thereduction in water are inversely proportional to (cross to) each other.Therefore, it is considered important to balance them.

In this invention, the pulsed laser light is emitted by continuousoscillation and can be intermittently irradiated onto the thin film byrelatively moving the thin film with respect to the pulsed laser light(Structure 6).

Herein, “continuous oscillation” represents carrying out oscillation inthe continuous oscillation mode and represents continuously carrying outoscillation for a certain time (e.g. 1 minute or more) with no cessationperiod. In order to prevent damage to a laser irradiation apparatus, itis necessary to cease the oscillation after continuously carrying outthe oscillation for the certain time.

In the case of the Structure 6, one or both of the substrate and thelaser light may be moved.

In the case of the Structure 6, the structure of the apparatus becomescomplicated and, since a portion where the irradiation durabilityevaluation is not required is also irradiated with the pulsed laserlight, it is rather wasteful, while, the conditions can be closer to theconditions of actual scanner exposure. In terms of more reproducing theconditions of the scanner exposure, it is preferable to relatively movethe thin film, but in terms of carrying out an evaluation more easilyand in a shorter time, the Structure 4 is considered more suitable. Itis preferable to select the method according to the situation.

In this invention, the pulsed laser light is preferably irradiated ontothe thin film in a humidity-controlled atmosphere (Structure 7).

As a condition of use in the scanner exposure, there is an environmentwhere the humidity is controlled at 35 to 50% RH (Relative Humidity)like in a clean room, or an environment which is controlled at a lowhumidity of 10 to 0% RH as a measure to counter haze. It is preferableto carry out an evaluation according to such a condition of use in thescanner exposure.

In this invention, the pulsed laser light is preferably irradiated ontothe thin film in an environment where an amount of a chemicalcontaminant in an atmosphere is controlled (Structure 8).

This is for reducing the occurrence of haze. This is because it has beenfound that when the irradiation conditions of the pulsed laser light arechanged, haze occurs or does not occur depending on irradiationconditions.

In this invention, the thin film may be a light-semitransmissive filmmade of a material composed mainly of a compound containing thetransition metal, silicon, and one or more elements selected from oxygenand nitrogen (Structure 9).

This is because, as described above, when the thin film is thelight-semitransmissive film (e.g. phase shift film) made of the materialcontaining the transition metal and silicon, the phenomenon remarkablyoccurs in which the transmittance and the phase difference change andfurther the line width changes (increases) due to the irradiation of ArFexcimer laser light (wavelength: 193 nm).

Herein, as the transition metal, use can be made of molybdenum,tantalum, tungsten, titanium, chromium, hafnium, nickel, vanadium,zirconium, ruthenium, rhodium, or the like.

In this invention, the light-semitransmissive film may be made of amaterial containing, in addition to the transition metal, at least oneof nitrogen, oxygen, carbon, hydrogen, inert gases (helium, argon,xenon, etc.), and so on.

The light-semitransmissive film may comprise, for example, a transitionmetal silicide, a transition metal silicide nitride, a transition metalsilicide oxynitride, or a transition metal silicide oxide.

In this invention, the light-semitransmissive film may have asingle-layer structure, a two-layer structure comprising alow-transmittance layer and a high-transmittance layer, or a multilayerstructure.

The light-semitransmissive film may be of the high-transmittance type.The high-transmittance type has a relatively high transmittance of 10%to 30% while the transmittance is normally 1% to less than 10%.

In this invention, the thin film may be a light-shielding film(Structure 10).

This is because the problem of irradiation durability also applies tothe light-shielding film.

The light-shielding film may have a single-layer structure or aplural-layer structure or may be a composition gradient film.

The light-shielding film may comprise an antireflection layer.

The light-shielding film may have a three-layer structure comprising aback-surface antireflection layer, a light-shielding layer, and afront-surface antireflection layer.

The light-shielding film may have a two-layer structure comprising alight-shielding layer and a front-surface antireflection layer.

In this invention, the light-shielding film may be made of a materialcontaining, in addition to the transition metal and silicon, at leastone of nitrogen, oxygen, carbon, hydrogen, inert gases (helium, argon,xenon, etc.), and so on. The light-shielding film may comprise, forexample, a transition metal silicide, a transition metal silicidenitride, a transition metal silicide oxynitride, or a transition metalsilicide oxide.

In this invention, the light-shielding film may be made of a materialcontaining, in addition to the transition metal, at least one ofnitrogen, oxygen, carbon, hydrogen, inert gases (helium, argon, xenon,etc.), and so on.

In this invention, when the light-shielding film is made of molybdenumsilicide compounds, the light-shielding film may have, for example, atwo-layer structure comprising a light-shielding layer (MoSi or thelike) and a front-surface antireflection layer (MoSiON or the like) or athree-layer structure further comprising a back-surface antireflectionlayer (MoSiON, MoSiN, or the like) between the light-shielding layer andthe substrate.

In a mask blank of this invention, the irradiation durability of a thinfilm is evaluated and guaranteed by the thin film evaluation methodaccording to any one of the Structures 1 to 10 (Structure 11).

The guarantee of a mask blank can be achieved by producing athin-film-coated substrate for evaluation, evaluating the irradiationdurability of a thin film, obtaining conditions (composition, filmforming conditions, etc.) satisfying the irradiation durabilityevaluation criterion, and producing a mask blank using the obtainedconditions.

Alternatively, the guarantee of a mask blank can be achieved byevaluating a thin film by the above-mentioned evaluation method eachtime the thin film is formed on a transparent substrate.

The evaluation result may be attached to a case receiving therein themask blank and provided to a mask manufacturing department (mask maker).In this case, the evaluation result is recorded on a paper medium or astorage medium (flexible disk, CD, etc.) and attached to the mask blankcase.

According to such a mask blank of which the irradiation durability isguaranteed, even when a transfer mask is manufactured by patterning thethin film and then is subjected to actual scanner exposure and thecumulative exposure amount reaches 10 kJ/cm², there is obtained aneffect that the CD change can be 5 nm or less and further 3 nm or less.

By intermittently irradiating the pulsed laser light onto a fixedportion, it is possible to carry out an evaluation having a highercorrelation with the result of an irradiation durability evaluation byactual scanner exposure and thus it is possible to carry out ahigh-accuracy irradiation durability evaluation with only a smalldifference from the result of the irradiation durability evaluation byactual scanner exposure as compared with the case where the pulsed laserlight is continuously irradiated onto the fixed portion.

In contrast, in the case of a mask blank of which the irradiationdurability is evaluated by continuously irradiating the pulsed laserlight onto a thin film, it is not possible to guarantee that thedifference from the result of the irradiation durability evaluation byactual scanner exposure is small. As a consequence, for example, thereis an inconvenience that it is possible, in a simple evaluation, tooverestimate (judge good) the irradiation durability of the thin filmwhich should be evaluated defective with a large change (increase) inthe line width according to the result of an irradiation durabilityevaluation by actual scanner exposure. On the other hand, for example,there is an inconvenience that it is possible, in a simple evaluation,to underestimate (judge defective) the irradiation durability of thethin film which should be evaluated good with a small change (increase)in the line width according to the result of an irradiation durabilityevaluation by actual scanner exposure. According to the mask blank ofthis invention, there is no such an inconvenience.

A transfer mask of this invention is manufactured by using the maskblank according to the Structure 11 and patterning the thin film(Structure 12).

By manufacturing such a transfer mask using the mask blank of which theirradiation durability is guaranteed, even when actual scanner exposureis carried out and the cumulative exposure amount reaches 10 kJ/cm²,there is obtained an effect that the CD change can be 5 nm or less andfurther 3 nm or less.

A transfer mask manufacturing method of this invention is a method ofmanufacturing a transfer mask adapted to be applied with ArF excimerlaser exposure light and comprising a thin film formed with a pattern ona transparent substrate,

-   -   wherein the transfer mask comprises an evaluation pattern formed        by the thin film, and    -   the irradiation durability of the thin film is evaluated by        intermittently irradiating pulsed laser light onto the        evaluation pattern (Structure 14).

The evaluation pattern formed by the thin film can be provided in anarea outside of a transfer pattern forming area (e.g. 132 mm×132 mm) ofthe transfer mask.

By evaluating the irradiation durability of a thin film each time such atransfer mask is manufactured as described above, the irradiationdurability of the transfer masks can be guaranteed individually. Forexample, even if transfer masks are manufactured using mask blanks ofthe same specification, the irradiation durability may differ dependingon a difference in the transfer mask manufacturing processes, but withthe above-mentioned structure, the irradiation durability of thetransfer masks can be guaranteed with higher accuracy.

The evaluation result may be attached to a case receiving therein thetransfer mask and provided to a semiconductor manufacturing department(device maker). In this case, the evaluation result is recorded on apaper medium or a storage medium (flexible disk, CD, etc.) and attachedto the transfer mask case.

A semiconductor device manufacturing method of this invention comprisesforming a circuit pattern on a semiconductor wafer using the transfermask according to the Structure 12 or using the transfer maskmanufactured by the transfer mask manufacturing method according to theStructure 14 (Structure 13 or 15).

Using the transfer mask of this invention, a transfer pattern is exposedand transferred onto a resist film on a semiconductor wafer as atransfer target. Use can be made of an exposure apparatus of theimmersion type with annular illumination which uses an ArF excimer laseras a light source. Specifically, by setting the transfer mask on a maskstage of the exposure apparatus, a transfer pattern is exposed andtransferred onto a resist film for ArF immersion exposure formed on asemiconductor wafer. Then, the exposed resist film is developed, therebyforming a resist pattern. Then, using the resist pattern, a circuitpattern is formed on the semiconductor wafer.

Using the transfer mask of this invention, it is possible to guaranteethe manufacture of a semiconductor device of the DRAM half-pitch (hp) 32nm generation.

This invention includes an invention of an evaluation method whichevaluates the thin film irradiation durability by intermittentlyirradiating pulsed laser light onto a thin film made of a materialcontaining a transition metal and formed on a transparent substrate.

This invention includes an invention of a method which evaluates andguarantees the thin film irradiation durability based on the fact thatthe thin film CD change is 5 nm or less when pulsed laser light isintermittently irradiated onto a thin film pattern made of a materialcontaining a transition metal and formed on a transparent substrate.

In this invention, ArF excimer laser light is preferable as the pulsedlaser light. This is because the above-mentioned phenomenon of the linewidth change (increase) is remarkably observed in the case ofshort-wavelength exposure light such as ArF excimer laser light. This isconsidered to be also related with the generation of ozone around thewavelength (193 nm) of ArF excimer laser light or the like.

In this invention, the resist is preferably a chemically amplifiedresist. This is because the chemically amplified resist is suitable forhigh-accuracy processing.

In this invention, the resist is preferably a resist for electron beamwriting. This is because the resist for electron beam writing issuitable for high-accuracy processing.

This invention is applicable to an electron-beam-writing mask blankadapted to be formed with a resist pattern by electron beam writing.

In this invention, the transparent substrate is not particularly limitedas long as it has transparency at an exposure wavelength to be used. Inthis invention, a quartz substrate and various other glass substrates(e.g. CaF₂ substrate, soda-lime glass substrate, alkali-free glasssubstrate, aluminosilicate glass substrate, etc.) can be used. Amongthem, the quartz substrate is particularly suitable for this inventionbecause it has high transparency in the wavelength range of ArF excimerlaser light.

In this invention, the transfer mask may be a binary mask that does notuse the phase shift effect, or a phase shift mask. The transfer mask maybe a reticle.

The phase shift mask may be a phase shift mask of the halftone type(tri-tone type), the Levenson type, the auxiliary pattern type, theself-aligned type (edge-enhanced type), or the like or an enhancer mask.

In this invention, in addition to the light-semitransmissive film or thelight-shielding film and its pattern, another thin film and its patterncan be formed.

For example, in the case where the material of thelight-semitransmissive film or the light-shielding film is a transitionmetal silicide, a material of the other thin film can be composed of amaterial having etching selectivity (etching resistance) to thelight-semitransmissive film or the light-shielding film, such aschromium, a chromium compound in which an element such as oxygen,nitrogen, or carbon is added to chromium, another transition metal,another transition metal silicide, or the like.

On the other hand, for example, in the case where the material of thelight-semitransmissive film or the light-shielding film is a transitionmetal (e.g. a material containing chromium), a material of the otherthin film can be composed of a material having etching selectivity(etching resistance) to the light-semitransmissive film or thelight-shielding film, such as a silicide of the transition metal,another transition metal, another transition metal silicide, or thelike.

The other thin film may be a light-shielding film which is formed on theupper or lower side of the light-semitransmissive film (e.g. phase shiftfilm), an etching mask film, an etching stopper film, or the like. Asthe other thin film, use is made of, for example, a material containingchromium.

In this invention, as the material containing chromium, use can be madeof chromium (Cr) alone or a material containing chromium (Cr) and one ormore elements selected from nitrogen (N), oxygen (O), carbon (C),hydrogen (H), helium (He), and so on. For example, use can be made ofCr, CrN, CrO, CrNO, CrNC, CrCON, or the like or a material containing,in addition thereto, hydrogen (H) or helium (He).

In this invention, use can be made of, for example, a fluorine-based gassuch as SF₆, CF₄, C₂F₆, or CHF₃ or a mixed gas of such a fluorine-basedgas and He, H₂, N₂, Ar, C₂H₄, O₂, or the like for dry-etching the thinfilm containing the transition metal and silicon.

In this invention, use can be made of a dry etching gas in the form of amixed gas containing a chlorine-based gas and an oxygen gas fordry-etching the chromium-based thin film.

In this invention, as the chlorine-based gas for use in the dry etching,use can be made of, for example, Cl₂, SiCl₄, HCl, CCl₄, CHCl₃, or thelike.

According to this invention, by intermittently irradiating pulsed laserlight onto a fixed portion, it is possible to carry out a high-accuracyirradiation durability evaluation with only a small difference from theresult of an irradiation durability evaluation by actual scannerexposure as compared with the case where the pulsed laser light iscontinuously irradiated onto the fixed portion. As a consequence, anefficient and high-accuracy irradiation durability evaluation isenabled.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1, (1) to (5) are exemplary cross-sectional views showing theprocesses of manufacturing a phase shift mask;

FIGS. 2, (1) to (6) are exemplary cross-sectional views showing theprocesses of manufacturing a binary mask;

FIG. 3 is a diagram showing the outline of an irradiation durabilityevaluation apparatus (ArF excimer laser irradiation apparatus); and

FIG. 4 is an exemplary diagram for explaining the intermittentirradiation.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS Examples

Hereinbelow, this invention will be described in more detail withreference to Examples.

Example 1 and Comparative Example 1 (Manufacture of Mask Blank)

As shown in FIG. 1, (1), using a synthetic quartz glass substrate havinga 6-inch square size with a thickness of 0.25 inches as a transparentsubstrate 1, a light-semitransmissive film 2 made of molybdenum,silicon, and nitrogen was formed on the transparent substrate 1.

Specifically, using a mixed target of molybdenum (Mo) and silicon (Si)(Mo:Si=10 at %:90 at %), reactive sputtering (DC sputtering) was carriedout by setting the power of a DC power supply to 3.0 kW in a mixed gasatmosphere of argon (Ar), nitrogen (N₂), and helium (He) (gas flow ratesAr:8 sccm, N₂:72 sccm, He:100 sccm) at a gas pressure of 0.3 Pa, therebyforming a MoSiN film made of molybdenum, silicon, and nitrogen to athickness of 69nm on the transparent substrate. Then, a heat treatmentwas applied to the substrate formed with the MoSiN film. Specifically,using a heating furnace, the heat treatment was carried out in theatmosphere at a heating temperature of 450° C. for a heating time of 1hour.

This MoSiN film had a transmittance of 6.1% with a phase difference of178.2 degrees at a wavelength (193 nm) of ArF excimer laser light.

This MoSiN film was analyzed by XPS (X-ray Photoelectron Spectroscopy).As a result, the composition of the MoSiN film was such that Mo:4.1 at%, Si:35.6 at %, and N:60.3 at %.

In this manner, a phase shift mask blank was manufactured. (Manufactureof Transfer Mask)

Then, on the mask blank thus obtained, a chemically amplified positiveresist for electron beam writing (PRL009: manufactured by FUJIFILMElectronic Materials Co., Ltd.) was coated to form a resist film 3 (seeFIG. 1, (1)). The resist film 3 was formed by spin coating using aspinner (spin coating apparatus).

Then, using an electron beam writing apparatus, a required pattern waswritten on the resist film 3 and, thereafter, the resist film 3 wasdeveloped with a predetermined developer, thereby forming a resistpattern 3 a (see FIGS. 1, (2) and (3)).

Then, using the resist pattern 3 a as a mask, the light-semitransmissivefilm (MoSiN film) 2 was dry-etched, thereby forming alight-semitransmissive film pattern 2 a (see FIG. 1, (4)). A mixed gasof SF₆ and He was used as a dry etching gas.

Then, the remaining resist pattern was stripped, thereby obtaining aphase shift mask (see FIG. 1, (5)).

There was almost no change in the composition, transmittance, and phasedifference of the light-semitransmissive film as compared with those atthe time of the manufacture of the mask blank.

(Evaluation)

The durability against ArF excimer laser light irradiation was examinedfor the light-semitransmissive film (MoSiN film) pattern of the phaseshift mask thus obtained.

In Example 1, the conditions of the ArF excimer laser light irradiationwere as follows. Specifically, using an ArF excimer laser oscillation(irradiation) apparatus (see FIG. 3), the intermittent irradiation wascarried out in an environment (atmosphere) of relative humidity 35% RHfor 15 hours under the conditions such that the oscillation frequencywas set to 500 Hz, the energy density per pulse was set to 10mJ/cm²/pulse, the number of pulses to be continuously emitted was set to10, the time for this event (time required for continuously emitting 10pulses) was set to 20 ms, the pulse width was set to 5 ns, and thecessation period (interval period) after the continuous pulse emission(continuous oscillation) was set to 500 ms (see FIG. 4). The cumulativeexposure amount was set to 10 kJ/cm².

As shown in FIG. 3, ArF excimer laser light is irradiated from thetransparent substrate side of a transfer mask (phase shift mask) 200. Inthis event, the transfer mask is disposed in a chamber 300 which iscontrolled in the above-mentioned atmosphere.

In Comparative Example 1, the conditions of the ArF excimer laser lightirradiation were as follows. Specifically, using an ArF excimer laseroscillation (irradiation) apparatus (see FIG. 3), the irradiation wascarried out in an environment (atmosphere) of relative humidity 35% RHfor 1 hour under the conditions of a continuous oscillation mode suchthat the oscillation frequency was set to 200 Hz, the energy density perpulse was set to 20 mJ/cm²/pulse, and the pulse width was set to 5 ns.The cumulative exposure amount was set to 10 kJ/cm².

Before and after the ArF excimer laser light irradiation under theconditions of Example 1, the CD change in a 200 nm line-and-spacepattern was 6 nm. The difference between this value and a CD change whenthe exposure equivalent to the cumulative exposure amount of 10 kJ/cm²was carried out by a scanner was 1 nm or less. Thus, the correlationbetween them was good.

Before and after the ArF excimer laser light irradiation under theconditions of Comparative Example 1, the CD change in a 200 nmline-and-space pattern was 15 nm. The difference between this value andthe CD change when the exposure equivalent to the cumulative exposureamount of 10 kJ/cm² was carried out by the scanner was about 10 nm.Thus, the correlation between them was not good.

Example 2 and Comparative Example 2 (Manufacture of Mask Blank)

As shown in FIG. 2, using a synthetic quartz glass substrate having a6-inch square size with a thickness of 0.25 inches as a transparentsubstrate 1, a MoSiN film (light-shielding layer) and a MoSiON film(front-surface antireflection layer) were respectively formed as alight-shielding film 10 on the transparent substrate 1 (FIG. 2, (1)).

Specifically, using a mixed target of molybdenum (Mo) and silicon (Si)(Mo:Si=21 at %:79 at %), reactive sputtering (DC sputtering) was carriedout in a mixed gas atmosphere of argon (Ar) and nitrogen (N₂), therebyforming a light-shielding layer (MoSiN film, Mo:Si:N=14.7 at %: 56.2 at%: 29.1 at %) to a thickness of 50 nm on the transparent substrate 1.

Then, using a mixed target of molybdenum (Mo) and silicon (Si) (Mo:Si=4at %:96 at %), reactive sputtering (DC sputtering) was carried out in amixed gas atmosphere of argon (Ar), oxygen (O₂), nitrogen (N₂), andhelium (He), thereby forming a front-surface antireflection layer(MoSiON film, Ma:Si:O:N=2.6 at %:57.1 at %:15.9 at %:24.4 at %) to athickness of 10 nm on the light-shielding layer.

The elements of the respective layers (light-shielding film) wereanalyzed by the Rutherford backscattering spectrometry.

The total thickness of the light-shielding film 10 was set to 60 nm. Theoptical density (OD) of the light-shielding film 10 was 3.0 at awavelength 193 nm of ArF excimer laser exposure light.

Then, the above-mentioned substrate was heat-treated (annealed) at 450°C. for 1 hour.

Then, an etching mask film 20 that is a chromium-based thin film wasformed on the light-shielding film 10 (FIG. 2, (1)).

Specifically, using a DC magnetron sputtering apparatus and using achromium target, the film formation was carried out in a mixed gasatmosphere of argon (Ar), carbon dioxide (CO₂), nitrogen (N₂), andhelium (He), thereby forming an etching mask film (CrOCN film,Cr:O:C:N=33.0 at %:38.9 at %:11.1 at %:17.10 at %) to a thickness of 15nm.

The elements of the CrOCN film (etching mask film) were analyzed by theRutherford backscattering spectrometry.

In this manner, a binary mask blank formed with the light-shielding filmfor ArF excimer laser light exposure was obtained. (Manufacture ofTransfer Mask)

Then, on the mask blank thus obtained, a chemically amplified positiveresist for electron beam writing (exposure) (PRL009: manufactured byFUJIFILM Electronic Materials Co., Ltd.) was coated by a spin-coatingmethod to form a resist film 100 with a thickness of 100 nm (FIG. 2,(1)).

Then, using an electron beam writing apparatus, a required pattern waswritten on the resist film 100 and, thereafter, the resist film 100 wasdeveloped with a predetermined developer, thereby forming a resistpattern 100 a (FIG. 2, (2)).

Then, using the resist pattern 100 a as a mask, the etching mask film 20was dry-etched, thereby forming an etching mask film pattern 20 a (FIG.2, (3)). A mixed gas of Cl₂ and O₂ (Cl₂:O₂=4:1) was used as a dryetching gas.

Then, the remaining resist pattern 100 a was removed (FIG. 2, (4)).

Then, using the etching mask film pattern 20 a as a mask, thelight-shielding film 10 was dry-etched using a mixed gas of SF₆ and He,thereby forming a light-shielding film pattern 10 a (FIG. 2, (5)).

Then, the etching mask film pattern 20 a was removed by dry etching witha mixed gas of Cl₂ and O₂ (Cl₂:O₂=4:1), thereby obtaining a binary mask(FIG. 2, (6)).

(Evaluation)

The durability against ArF excimer laser light irradiation was examinedfor the light-shielding film pattern 10 a of the binary mask thusobtained.

In Example 2, the conditions of the ArF excimer laser light irradiationwere as follows. Specifically, using an ArF excimer laser oscillation(irradiation) apparatus (see FIG. 3), the intermittent irradiation wascarried out in an environment (atmosphere) of relative humidity 35% RHfor 15 hours under the conditions such that the oscillation frequencywas set to 500 Hz, the energy density per pulse was set to 10mJ/cm²/pulse, the number of pulses to be continuously emitted was set to10, the time for this event (time required for continuously emitting 10pulses) was set to 20 ms, the pulse width was set to 5 ns, and thecessation period (interval period) after the continuous pulse emission(continuous oscillation) was set to 500 ms (see FIG. 4). The cumulativeexposure amount was set to 10 kJ/cm².

In Comparative Example 2, the conditions of the ArF excimer laser lightirradiation were as follows. Specifically, using an ArF excimer laseroscillation (irradiation) apparatus (see FIG. 3), the irradiation wascarried out in an environment (atmosphere) of relative humidity 35% RHfor 1 hour under the conditions of a continuous oscillation mode suchthat the oscillation frequency was set to 200 Hz, the energy density perpulse was set to 20 mJ/cm²/pulse, and the pulse width was set to 5 ns.The cumulative exposure amount was set to 10 kJ/cm².

Before and after the ArF excimer laser light irradiation under theconditions of Example 2, the CD change in a 200 nm line-and-spacepattern was 3 nm. The difference between this value and a CD change whenthe exposure equivalent to the cumulative exposure amount of 10 kJ/cm²was carried out by a scanner was 1 nm or less. Thus, the correlationbetween them was good.

Before and after the ArF excimer laser light irradiation under theconditions of Comparative Example 2, the CD change in a 200 nmline-and-space pattern was 5.5 nm. The difference between this value andthe CD change when the exposure equivalent to the cumulative exposureamount of 10 kJ/cm² was carried out by the scanner was about 3 nm. Thus,the correlation between them was not good.

While this invention has been described with reference to the Examples,this invention is not limited thereto. Various changes that can beunderstood by a person skilled in the art can be made to the structuresand details of this invention within the spirit and scope of thisinvention described in claims.

What is claimed is:
 1. A mask blank for manufacturing a transfer maskadapted to be applied with ArF excimer laser exposure light, comprising:a transparent substrate; and a thin film formed on the transparentsubstrate, wherein the thin film is evaluated for irradiation durabilitythereof by intermittently irradiating pulsed laser light onto a thinfilm pattern and is guaranteed for the irradiation durability thereof onthe basis of the evaluation result.
 2. The mask blank according to claim1, wherein the thin film is made of a material containing a transitionmetal and silicon.
 3. The mask blank according to claim 2, wherein thethin film is made of a material containing, in addition to thetransition metal and silicon, at least one of nitrogen, oxygen, carbon,hydrogen, and an inert gas.
 4. The mask blank according to claim 2,wherein the transition metal is selected from molybdenum, tantalum,tungsten, titanium, chromium, hafnium, nickel, vanadium, zirconium,ruthenium, or rhodium.
 5. The mask blank according to claim 1, whereinthe thin film is a light-semitransmissive film.
 6. The mask blankaccording to claim 1, wherein the thin film is a light-shielding film.7. The mask blank according to claim 1, wherein the evaluation of thethin film is carried out each time when the thin film is formed on thetransparent substrate.
 8. The mask blank according to claim 1, whereinthe evaluation of the thin film is carried out by using athin-film-coated substrate for evaluation with the thin film pattern. 9.A transfer mask manufactured by using the mask blank according to claim1 and patterning the thin film.
 10. A method of manufacturing a maskblank for manufacturing a transfer mask adapted to be applied with ArFexcimer laser exposure light, the mask blank being produced by usingpredetermined conditions, wherein the predetermined conditions arepreviously obtained by: intermittently irradiating pulsed laser lightonto a thin-film-coated substrate for evaluation with a thin filmpattern formed on a transparent substrate to thereby evaluateirradiation durability of the thin film; and then obtaining conditions,as the predetermined conditions, satisfying an evaluation criterion ofthe irradiation durability.
 11. The method according to claim 10,wherein the condition is a composition.
 12. The method according toclaim 10, wherein the conditions are film forming conditions.
 13. Themethod according to claim 10, wherein the pulsed laser light isintermittently irradiated to a degree that does not cause heating of thethin film.
 14. The method according to claim 10, wherein the pulsedlaser light is emitted by intermittent oscillation and is irradiatedonto the thin film at its fixed position.
 15. The method according toclaim 14, wherein a cessation period of the intermittent oscillation is100 msec to 3000 msec.
 16. The method according to claim 10, wherein thepulsed laser light is emitted by continuous oscillation and isintermittently irradiated onto the thin film by relatively moving thethin film with respect to the pulsed laser light.
 17. The methodaccording to claim 10, wherein the pulsed laser light is irradiated ontothe thin film in a humidity-controlled atmosphere.
 18. The methodaccording to claim 10, wherein the pulsed laser light is irradiated ontothe thin film in an environment where an amount of a chemicalcontaminant in an atmosphere is controlled.
 19. A method ofmanufacturing a transfer mask adapted to be applied with ArF excimerlaser exposure light and comprising a transparent substrate and a thinfilm formed with a pattern including an evaluation pattern on thetransparent substrate, wherein irradiation durability of the thin filmis evaluated by intermittently irradiating pulsed laser light onto theevaluation pattern.
 20. The method according to claim 19, wherein thepulsed laser light is intermittently irradiated to a degree that doesnot cause heating of the thin film.
 21. The method according to claim19, wherein the pulsed laser light is emitted by intermittentoscillation and is irradiated onto the thin film at its fixed position.22. The method according to claim 21, wherein a cessation period of theintermittent oscillation is 100 msec to 3000 msec.
 23. The methodaccording to claim 19, wherein the pulsed laser light is emitted bycontinuous oscillation and is intermittently irradiated onto the thinfilm by relatively moving the thin film with respect to the pulsed laserlight.
 24. The method according to claim 19, wherein the pulsed laserlight is irradiated onto the thin film in a humidity-controlledatmosphere.
 25. The method according to claim 19, wherein the pulsedlaser light is irradiated onto the thin film in an environment where anamount of a chemical contaminant in an atmosphere is controlled.